Electrical connector



Feb. 16, 1965 F. HAMMOND ETAL ELECTRICAL CONNECTOR Filed Jan. 28, 1963INVENTORS Frank HAMMOND Ernesi' F. ROBIN Pierre GAUTHIER AGENT UnitedStates Patent Frank Hammond, Terrebonne, Quebec, Ernest IF. Robin,

Montreal, Quebec, and Pierre Gauthier, (Ihateauguay,

Quebec, Canada, to Northern Electric Company Limited, Montreal, Quebec,flan-aria Filed Ian. 28, E63, Ser. No. 254;? 9 Qlaims. (Cl. 33911i3)This invention relates to an electrical connector which is particularlyadaptable for making temporary test con nections.

In the telephone industry it is common practice to insert protectivedevices at critical points along a telephone line between the outsideplant and the central ofiice. Protector blocks, connected across theline, guard against excessive line voltages. By construction theprotector blocks provide points suitable for ready connection to pairsof test set leads, used for checking circuit continuity.

The industry has long had need for a connector which could readily makesimultaneous connection of a multiplicity of perhaps 50 pairs of testconnections to protector blocks.

Protector blocks normally consist of a small piece of carbon mounted ina porcelain block having a channel along its length on one side. Theprotector blocks, in turn, are mounted on a terminal block. A ilatmetallic spring, integral with the terminal block, fits into the channelin the protector block thus holding it in position. The springfurthermore provides the electrical connection between the carbon, whichprotrudes into the channel, and the line. The protector blocks aremounted in pairs along the length of the terminal block.

There has been a problem facing the industry in finding a satisfactorymeans, having facility of operation, for firmly connecting the leads tothe protector block springs.

Prior to applicants invention it was well known to use a device wherebyseveral pairs of spaced contacts, of a resilient metal were spread, uponforced contact with the protector block springs, to engage the springs.Since each pair of contacts had to be individually spread apart whenforced against the corresponding pair of springs, the limitations of thedevice depended upon the collective spreading force required for theseveral contact pairs. A known connector of this type had, for example,a maximum of about contact pairs.

Applicants have discovered that by utilizing a spring controlledpivoting action an electrical connector is provided which permits theconnection of a much greater number of contacts, thereby overcoming themain disadvantage prevalent in the prior art proposals. The pivotingaction is manually initiated to spread the contacts. Once the contactsare in spread condition and the connectoris placed adjacent theprotector block springs, the manual control is released and the contactsassume their normal position to make contact with the springs. Theelectrical connector according to applicants invention comprises a pairof supporting members each carrying at least one electrical contact, themembers being connected by a resilient means which acts as a commonpivot therefor. Two contact spacing means are provided, the first actingresiliently on the members to pivot them about the resilient means in adirection such that the contacts are brought toward each other; and thesecond contact spacing means being arranged so'as when operated to acton the members to draw the ,contacts apart. The resilient means has asecond function in that it opposes the action of the first contactspacing means to limit the degree to which the lattercan force thecontacts toward each other.

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Another advantage of the connector according to the present invention isthat it may be used to simultaneously test circuits which are protectedby different sized protector blocks. This is accomplished by mounting atboth ends of the device stop members which may be indiw'dually adjustedto allow different depths of penetration between the contacts.Furthermore, the contacts, as well as being made of a resilient metal,are individually mounted to permit connection to blocks of differentthickmesses.

Preferred embodiments of the invention will now be described, by way ofexample, with reference to the accompanying drawings. The samereferenced designations will be used for similar parts in each figure ofthe drawings, in which:

FIGURE 1 is a perspective View of the preferred embodiment of amultiple-contact-pair electrical connector in its normal condition;

FIGURE 2 is a sectional view through line 2-2 of FIG. 1 showing a singlecontact pair in the normal connected position with a pair of protectorblocks and associated springs (outlined only);

FIGURE 3 is a sectional view of the electrical connector through thesame section as FIG. 2, showing the connector in the spread contactposition.

PEGURE 4 is a sectional view through line 44 of FIG. 1 illustrating, inparticular, the details of the adjustable stop member; and

FTGURE 5 is an expanded perspective view of a single contact,illustrating a typical configuration of metallic projections.

The basic principles of the connector can be most readily appreciated byreferring to FIGS. 2 and 3 of the drawings. Two supporting members i, 2,are shown, each member bearing at its lower extremity a contact 3, 4,respectively. A resilient means shown as a plate 5 is provided toprevent the members 1, 2 from meeting at their lower extremities andalso to act as a common pivot for the members 1, 2. A first contactspacing means shown as a volute spring 6 urges the lower extremities ofthe members ll, 2 (and thus the contacts 4-, 5) toward each other. Theplate 5 and spring 6 furthermore unify the device. A second contactspacing means shown as a pair of handles 7, one handle being affixed toeach of the members 1, 2, is arranged, when actuated, to move thecontacts 3, t apart by a pivoting action about the plate 5.

The members 1, 2 are made of an insulating material (eg. plastic) andare arranged in a substantially parallel, face-to-face relationship. Theplate 5 is made of flexible material, preferably spring steel, and issubstantially rectangular in shape. The plate 5 is rigidly affixed tothe members It, 2 and extends between the inner faces 8, 9 respectivelythereof, somewhat above the point of mount ing of the contacts 3, 4 andapproximately intermediate of the height of the members. The ends of thespring 6 are aflixed to the inner surfaces 8, S? of the members ll,

'2 respectively at a point above the plate 5 near the tops of themembers so that the plate 5 and the spring 6 are substantially parallel.

The spring 6 is preferably of the volu-te type particularly because ofthe inherent high retention of resiliency and also since, byconstruction, a volute spring olfers maximum safety to an operator whenthe spring is under pressure. if a coil Spllil." were used a shieldwould be required to overcome the hazard to the operator caused by theopen spacing of the coil turns.

One of the handles 7 is mounted on each outer face 10, ll of the members1, 2 respectively near their tops in axial alignment with the spring 6.

The spring 6 is in compression at all times, consebeen overcome theplate becomes substantially rigid and impedes further pivoting actionthus preventing the con-. tacts 3, 4 from closing to a touchingposition.

The handles 7 are arranged on the members 1, 2 at a position to produceoptimum pivoting of the members the spring 6 when pressure is applied tothe handles. When the handles 7 are drawn together the spring 6 isplaced in further compression and the members 1, 2 are pivoted about theplate in a direction opposite that effected by the spring 6 under normalconditions. Consequently, the contacts 3, 4 are spread apart, thespacing between contacts now being greater than the maximum distancebetween the engaging portions of theprotector 'blocx springs with whichthe device is to make connection. With the handles drawn together theconnector is placed in juxtaposition with the protector block springs,the bandies '7 are released and the spring 6 expands, pivoting themembers ll, 2 until the contacs 3, 4- have assumed proper elecricalcontact with the springs and the device retains this position withlittle or no external guidance.

FIGURE 2 illustrates the connector in its normal connected position withthe contacts 3, 4 connected with the protector block springs 12, 13respectively (in dotted outline form). FIGURE 3 illustrates theconnector in its spread contact position, there being an external forceapplied to the handles pushing them inwardly. If the force were to bereleased the contacts 3, 4 would assume a final position slightly closertogether than in the case where I they are connected with the protectorblock springs 12,13. This natural tendency oi the connector to close thecontacts to a slightly greater extent than when they are in theconnected position provides a force which holds the connector in theconnected position. The connection is aided by one or more metallicprojections 14 on each of the contacts 3, 4 (PEG. 5) which make contactwith the protector block springs, thus reducing slippage to a minimum. I

Each contact 3, t is electrically connected by wire 1 to a connection,shown as a commercial plug-in-type connector 16 (FIG. 1), which iscabled l? to the required test set.

The preferred embodiment of the connector is illus trated in FIG. 1which essentially shows a multiple of the connectors described withreference to FIGS. 2 and 3. In FIG. 1 the members ll, 2 are elongatedand each carries along its length a plurality of evenly spaced contacts3, 4 to provide a series of oposing contacts. In prace tiee the maximumnumber of contacts carried by each member 1, 2 could be as many as 5%).

Several plates 5 and springs dare located in a symmetrical fashion alougthe length of the members ll, 2 in order to provide a multiple effect ofa single plate 5 and spring 6 and to make the device rigid. The handles7 are pivotally' mounted centrally of the length of the members 1, 2.When not in use the handles '7 are rotated to a position approximatelyflush with the top of and parallel to the length of the'members ll, 2.An abutting means is suspended downwardly from each end plate 5. Eachabutting means comprises a solid block 18 prefen ably of an insulatingmaterial and depends from the end plate 5 between the lower extremitiesof the members 1, 2. Each block 18 is of such a width that as themembers 1, 2 pivot under the action of the springs 6 they abut theblocks, maintaining the contactsfi, a predetermined minimum distanceapart. This minimum distance is less a about the plate 5 in a directionopposite that eifected by An adjustable stop 1% is located at either endof the connectors. Each stop 1? comprises a threaded shaft 20 (FIG. 4)which engages a threaded bore in the abutting block 18 and in the endplate 5. Thestop 1.9 has attached thereto at one end an adjusting knob21 which protrudes above the end plate 5 and a stop-knob 22 whichextends downwardly between the contacts 3, 4. The stop-knob 22 isadapted to bear onthe portion 23 of the protector blocks between thesprings 12 and 13 (FIG. 2) to control the penetration of the blocksbetween the members l, 2 of the connector and thereby the position ofthe contacts 3, 4 along the lengths of the springs 12 and 13.Furthermore, the two adjustable stops 19 may be adjustedindependently'of one another. the protector blocks 23 vary in size alongthe length ofthe terminal strip. Consequently, for one set' ofmeasurements the requirement exists that the protector blocks mustpenetrate the connector to different extents along the length of theconnector to ensure proper electrical contact at each spring. A certaindegree of adjustzibility may be eifected by adjusting the stop-knobs 22at either end of the device to different positions thus allowing for agraduated depth of penetration of the blocks along the length of theconnector.

A tooth-like member 24 is situated at one extreme end of the connectorrigidly atllxed to the abutting means '18 at that end, the member 24extending downwardly beyond the lowermost point of the contacts 5, 4.

As the connector is placed, in its spread contact condition, in'juxtaposition with a series of protector blocks along the terminalstrip, the tooth-like member 24 is placed in sliding engagement with thefree surface of the end-most protector block. Because ofthepredetermined spacing between the member 24% and the adjacent oppos:

ing contacts .3, ti and the uniform spacing between 'suc-.

cessive contact pairs, the connector is provided with a point ofreference longitudinally thereof; Consequently when the external forceis released from the handles 7 and the connector is allowed to assumeits normal condition in contact with the protector block springs, eachpair of opposing contacts 3, 4 are in position to assume a, satisfactoryelectrical connection with the' corresponding pair of protector blocksprings. To further ensure satisfactory connection, the contacts 3, 4are individuallymounted at 25, 26 respectively (see FIG. 2) and areformed of a resilient metal. These features ei'lect satisfactory connection regardless of normal variations in depth of pro.-

tector block or springdimensions.

In FIG. 1 the tooth-like member 24 has been removed from its actualposition afiixed to the block 18 for the sake of clarity. In FIG. 4 themember 24 is shown in its actual position. This sectional view alsoserves the purpose of more lucidly illustrating the structure andposition of the-block 18 and the adjustable stop 1%.

Additional features of the preferred embodiment of the connector areevident in FIG. 1. These features include two pairs of transparentshields one pair being affixed to each of the side and top of'themembersl, 2.

These shields are provided both to protect the operator of than thedistance between the contacts 3, t-when they are the connector from themoving parts thereof, and to provent any appreciable amount'ofextraneous matter from 7 entering the connector and thus impairing itsoperation.

The side shields 27, 28 are L shaped in cross section, extendingdownwardly from the members 1, 2 respectively and inwardly slightlybelow the bottom of the contacts 3, 4 to form, in effect, an incompleteencasement of the contacts. The shields 27, 28 are flexibly attached tothe members 1, 2 respectively to prevent interference with theprotectorblocks while the connection is.being made.

i The top shields 29, 30 ailixed to the members 1,. 2 respectively, eachextend partially across the top of the device and overlap, shield 13%extending above shield 29. When the members 1, 2 arepivoted under thesection of the handles 7 shield 38 overrides shield '29.

Thus, according to applicants invention, an electrical It is often thecase that :3 connector has been provided that can be used advantageouslyto make a multiplicity of temporary test connections.

What is claimed is:

1. An electrical connector comprising a pair of supporting members, anelectrical contact carried by each supporting member, resilient meansproviding a common pivot for the members; first contact spacing meansspaced from said resilient means and acting resiliently on the membersto pivot them about the resilient means in a manner to move the contactstogether; the resilient means being in opposition to the first contactspacing means to limit the degree to which the latter moves the contactstogether; and a second contact spacing means arranged to act on themembers and operable to pivot them in a manner to move the contactsapart.

2. An electrical connector as defined in claim 1 wherein the resilientmeans is a flexible plate bridging the members; and the first contactspacing means is a compression spring mounted between the supportingmembers on the opposite side of the plate from the contacts; the springand the plate being arranged to provide mutual co-action so that thespring is in compression at all times.

3. An electrical connector as defined in claim 2 wherein the spring isof the volute type and the plate is spring steel, substantially uniformin thickness.

4. An electrical connector as defined in claim 2 wherein the secondcontact spacing means comprises a pair of handles mounted on thesupporting members on the same side of the plate as the compressionspring and adapted to be moved together to spread the contacts.

5. An electrical connector as defined in claim 2 including an abutmentsecured to the plate and interposed between the supporting members onthe same side of the plate as the contacts to prevent movement of themembers beyond a predetermined minimum spacing of the contacts.

6. An electrical connector as defined in claim 2 including an elongatedstop member mounted on the plate, the stop member being adjustablymovable in a direction at right angles to the plane of the plate betweenthe plate and the contacts.

7. An electrical connector as defined in claim 2 wherein at least oneprojection is formed on the surface of each contact at the point ofelectrical connection.

8. An electrical connector comprising a pair of elongated supportingmembers, a plurality of evenly spaced contacts carried by eachsupporting member along its length to provide a series of opposingcontacts; at least two flexible plates of substantially uniformthickness, one at each extremity of the connector, the plates bridgingthe supporting members to provide a common pivot for the supportingmembers; at least one compression spring acting between the supportingmembers on the opposite side of the plate from the contacts to pivotthem in a manner to urge the opposing contacts together, the spring andthe plates being arranged to provide mutual co-action so that the springis in compression at all times; means arranged to act on the supportingmembers to place the spring in further compression and pivot the membersabout the flexible plates in a manner to move the opposing contactsapart; an abutment secured to the plates at either end of the connectoron the same side of the plate as the contacts and interposed between thesupporting members to prevent movement of the members beyond apredetermined minimum spacing of the contacts; and elongated stopmembers mounted on the plate at each extremity 'of the connector, eachstop member being adjustably movable in a direction at right angles tothe plane of the plate between the plate and the contacts.

9. An electrical connector as defined in claim 8 wherein each contact isindividually mounted and has at least one projection formed on thesurface thereof at the point of electrical connection.

References Cited by the Examiner UNITED STATES PATENTS 1,923,901 8/33Winkie 339-74 2,103,891 12/37 Brown 339-108 2,261,761 11/41 Hanson et al339-255 X 2,428,057 9/47 Wilburn 339-255 X 2,445,981 7/48 VonVoigtlander 339-74 2,928,067 3/ 60 Broberg et a1 339-200 JOSEPH D.SEERS, Primary Examiner.

1. AN ELECTRICAL CONNECTOR COMPRISING A PAIR OF SUPPORTING MEMBERS, ANELECTRICAL CONTACT CARRIED BY EACH SUPPORTING MEMBER, RESILIENT MEANSPROVIDING A COMMON PIVOT FOR THE MEMBERS; FIRST CONTACT SPACING MEANSSPACED FROM SAID RESILIENT MEANS AND ACTING RESILIENTLY ON THE MEMBERSTO PIVOT THEM ABOUT THE RESILIENT MEANS IN A MANNER TO MOVE THE CONTACTSTOGETHER; THE RESILIENT MEANS BEING IN OPPOSITION TO THE FIRST CONTACTSPACING MEANS TO LIMIT THE DEGREE TO WHICH THE LATTER MOVES THE CONTACTSTOGETHER; AND A SECOND CONTACT SPACING MEANS ARRANGED TO ACT ON THEMEMBERS AND OPERABLE TO PIVOT THEM IN A MANNER TO MOVE THE CONTACTSAPART.